This Page is a product of Darwin Severe Weather Research.
It is an attempt to highlight the absence and thus inaccuracy of figures
pertaining to severe weather events in Darwin. The page features many newspaper
reports of severe weather, some personal events as told by individuals, severe
storm submission area, and general information area. It must be noted however
that the data on this site is provided from texts and data sheets as detailed
in the bibliography, and all personal accounts are always subject to
verification, and must not be instantly assumed factual, as with any recount of
an event, elaboration can occur.
The area in and around Darwin receives annually
approximately 92 thunder days, that is, a day when thunder is heard locally, so
it cannot be assumed that the whole of Darwin is in fact receiving a
thunderstorm for all of those days. Severe thunderstorms in the NT are grossed
at 9 per year. This represents 9% of the thunderdays per ratio. This figure is
realistic to a reasonable extent, however, residents living in the top end
argue this to be incorrect, and through simple newspaper clippings, we can
quite well disprove these figures. At present, it is known that the Darwin area
receives most of its severe weather during the period’s prior, and just after
the wet season. However it is also known that during the wet season itself,
whilst the lower atmosphere is most unstable (triggered by tropical lows
associated with ITCZ), Darwin receives the majority of its tornadic activity.
This very fact is subject to high criticism from groups that study and
interpret local conditions remotely by the use of figures and real time
tracking devices, eg; radar, upper air analysis. The areas south of Darwin,
'rural' are accepted to have high occurrences of severe thunderstorms (made
public by the Darwin Bureau of Meteorology in a media release), during which
some interesting damage occurs. These facts don’t make it into severe storm
frequency charts, and thus they are quite often overlooked. An issue of public
safety arises from this also with a complete absence of severe thunderstorm
advices and Warnings. Personal experience has proved this to be correct; the
areas around Humpty Doo, Adelaide River, Noonamah and Berry Springs have all
seen severe storms this season (2001).
·
Ratio
of severe storms to non severe storms in the NT
(note that this chart represents the whole NT, not just
the northern area, ‘top end’)
Severe storms are
said to be rare in the top end. The official Classification of a severe storm
is;
A Storm that produces one, or any combination of the following
features.
1. Hail, Diameter of
+2cm
2. Wind Gusts of
90km/hr or greater
3. Flash Floods
4. Tornadoes
As we can well expect, hail is an absolute rarity in the
top end. Obviously due to the high surface temperatures, and temps in the lower
levels making it almost impossible for the hail to survive its fall. (Although
hail was reported in Palmerston suburbs this season).
The storms detailed in this report contained wind gusts
well in excess of the severity benchmark, some instigated flash flooding, and
some had tornadoes within them. It is from a Northern Territory thunderstorm
that the national maximum wind gusts (non cyclonic) record is held.
This collection is only limited to my collection only, if
you live in the top end and have more data, photos, or media releases
pertaining to severe weather events please click here.
Tuesday December 5, 2000: media release "Waterspout
Rips Into Beach Resort"
· “Waterspout
Rips Into beach Resort”
· Actual
Image of Mandorah Tornado
Image courtesy of Jason Rainforest.
Damage Report:
This waterspout was spotted and reported to the Bureau of
Meteorology during its occurrence. One Australian Severe Weather Watchers
member was visiting and we both observed and photographed this. I personally
rang the bureau and was treated with a great deal of disbelief and apathy,
until obviously the next day when it became apparent of the damage it had
caused.
The spout started north of mandorah, and tracked into the
mandorah mainland uprooting trees, destroying the jetty shattering glass and
tearing a roof off a unit from the 'crabclaw' resort. Witnesses estimated the
spout to be about 40metres wide and several hundred metres high.
Damage from this particular tornado was estimated at
$20,000 . The BOMs Ian Sheppard stated that reports of waterspouts in the top
end are surely common, although their landfalls are quite rare.
Bureau Warning for this storm and tornado: NIL
Waterspout off Nightcliff 8th Feb., 2001
· Front
page image of Waterspout
This waterspout was spotted and photographed by locals of
Nightcliff, estimated to 100 - 150 metres high and 40m wide, this spout hovered
off the coast for over half an hour.
Damage: Nil
Warnings: NIL
October 28th, 2001
·
Severe Storm Rips
Through Rural Area
Severe storm rips through Noonamah ripping trees from the
ground (20 year old trees) and slight damage to property, fortunately in a
remote area with very little population density. BOM forecaster Mark
Kersemakers stated 'intense thunderstorms were common in the rural area this
time of year' Wind gusts from this storm 110km/hr. Power grid out.
Damage: Slight structural damage, vegetation etc
Warnings: NIL
Thursday 22nd November 2001
Pending scanned image of sunken sea containers..
Severe storms rip through Noonamah and Darwin. Tornado
and wind gusts of 127km/hr recorded, damage bill in the tens of thousands of
dollars. 5000 litre water tank dislodged and strewn onto the Stuart highway,
trees uprooted, car crushed under fallen trees, 4 2.4 tonne shipping containers
hurled into the ocean, after being thrown 30 feet in the air. Power grid out.
Damage: significant as detailed,
Warnings: NIL prior, STW issued during storm.
For every report detailed in this text, there are at
least three severe weather events in the rural area that get NO coverage by the
media, and no recognition from the BOM. Damage usually occurs in unpopulated
areas south of the city, where huge thunderstorms rage for hours at a time,
seemingly unobserved and non-affecting.
This is a small collection of media documented severe
weather events in and around the top end. The absence of warnings is of grave
concern to the residents of the top end, who are told that 'severe storms are
rare', 'tornadoes are rare' etc. However the damage detailed in this small
report alone highlights the need for Darwin residents to be aware of the risks,
and to a small extent, ignore the facade that 'severe storms are a rarity in
the top end' as I'm sure this report thoroughly disproves.
· Figures
Too cloudy, Even in City!
As this report suggests, the problem in the top end is the lack
of data. Amoung the first rains last
season was a load of confusion as to the actual rainfall figures. This is a huge problem, even in the city as
mentioned.
· Severe
Storm Study NT Figures, Cape Skew etc
These figures are provided for the analytical of you, and as
I must mention again, this refers to storms throughout the NT, not just the top
end. Data is severely lacking for areas
immediately south of Darwin where this web report places a lot of emphasis.
Other Parts to this
study:
MEDIA CAMPAIGN
For 4 weeks starting
Thurdsday 6th December, 94.5fm will be playing a commercial urging
remote listeners (station range is ideal) to call the MessageSave number and
report their experiences, and to detail if they have any photographic resources
pertaining to this. Results will be
posted at the end of the media campaign period.
NT STORM
EDUCATION
Awaiting further
resources, a page dedicated to life in Australias most Storm Prone and
lightning prone area.
No Copyright on data, Images sourced from below.
2001, Jacob D. Gray (outback@tropicalstorm.com)
Images courtesy of NT News, Jason Rainforest. Data collected from various BOM texts, above
dataset and frequency chart for ST: ‘dynamical classifications of severe
thunderstorms in the NT’.